Vacuum cleaner suction regulator



K. J. WAHLBORG VACUUM CLEANER SUCTION REGULATOR April 11, 1963 FiledJan. 14, 1958 VACUUM CLEANER SUCTION REGULATOR Karl John Wahlborg,Stockholm-Vallingby, Sweden, as-

signor to Aktiebolaget Electrolux, Stockholm, Sweden, a corporation ofSweden My invention relates to a suction regulator for varying thesuction elfect transmitted to a cleaning appliance in a suction line ofa vacuum cleaner.

It is an object of my invention to provide an improved suction regulatorof this type which is of simplified construction and effectivelyregulates the suction effect transmitted to a cleaning appliance in asuction line of a vacuum cleaner.

Another object of the invention is to provide an improved suctionregulator which automatically regulates the suction effect transmittedto a cleaning appliance responsive to a condition incident to a cleaningoperation effected by the cleaning tool.

A further object of the invention is to provide an improved suctionregulator which automatically regulates the suction effect transmittedto a cleaning appliance responsive to the forces produced and developedwith movement imparted to the cleaning appliance by an operator. Iaccomplish this by providing in a suction line of a vacuum cleaner apair of telescopically fitted hollow members in which one member isprovided with a slot which is covered or uncovered by the other memberto vary the size of a leakage port and determine the suction effectreaching the cleaning appliance. In the preferred embodiment the hollowmembers are biased to move apart with the aid of a resilient element toincrease the size of the leakage port, and arranged to move toward o eanother against the compression of the resilient element to reduce thesize of the leakage port. When the cleaning appliance is being movedback and forth over a rug or other surface being cleaned, the size ofthe leakage port is automatically regulated so that favorable operatingconditions will always prevail during a cleaning operation.

Further objects and advantages of my invention will become apparent asthe following description proceeds, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to thefollowing description taken in connection with the accompanying drawing,in which:

Fig. 1 is a perspective view of a suction cleaner having a cleaningappliance connected to a suction line provided with a suction regulatorembodying my invention;

Fig. 2 isan enlarged fragmentary perspective view, partly broken awayand in section, of the suction line shown in Fig. 1 to illustrate thesuction control more clearly; and

Fig. 3 is an exploded perspective view of the suction regulator shown inFig. 2 to illustrate details.

Referring to the drawing, I have shown my invention in connection with ahorizontal tank-type suction cleaner which includes a casing having anend cover 10a. The end cover 10a is provided with an inlet 10b to whicha suction hose 11 is adapted to be removably secured in any suitablemanner (not shown). Suitable cleaning appliances, such as a nozzle 14havinga suction inlet 14a,

2,978,733 Patented Apr. 11, 1961 for example, may be connected to, awand which in turn is connected to the outer free end of the hose 11 andthrough which air is drawn into the casing 10 by a suitable motor-fanunit (not shown) disposed therein. Dust and dirt entrained in the airduring a cleaning operation are separated from the air when the latterpasses through a dust collecting member (not shown) disposed in thecasing, and air from which dust and dirt have been removed is dischargedfrom the casing 10 at the end thereof opposite the end cover 10a.

The wand, which is normally at an acute angle to the vertical whenemployed to manipulate the nozzle 14 over a horizontal surface to becleaned, comprises outer and inner tubular members 12 and 13, the outertubular member 12 having an enlarged end section or socket 16 withinwhich the inner tubular member 13 telescopically fits. The socket 16 isformed with an opening 17 whose eifective size is changed responsive toaxial movement of the outer and inner tubular members 12 and 13 withrespect to one another, thereby regulating the suction eflt'ecttransmitted through the suction line from the casing 10 to the cleaningappliance 14,

In accordance with my invention, the telescopically fitting end sectionsof the outer and inner tubular members 12 and 13 form part of a suctionregulator 15 which also includes a hollow sleeve-like element 18 in theform of a split ring which is slit at 19 and externally threaded andprovided with spaced apart lugs or bosses 20 at its inner surface. Theelement 18, which is resilient in character, is mounted in position onthe inner tube 13 by expanding the element sufficiently to enable it tobe moved over such tube to a region at the immediate vicinity of slotsor openings 21. In its mounted position on the inner tubular member 13,the openings 21 receive the lugs 20 of the element 18 and the latterassumes its undistorted shape seen in Fig. 3, the element 18 in suchmounted position being in the position illustrated in Fig. 2.

The element 18 forms an externally threaded portion of the inner tube13, and, due to the inherent resilient character of the element, thelugs or bosses 20 are effectively held in the slots 21 so that theelement 18 forms a unitary part of the inner tube 13 and is alwaysmovable therewith.

The externally threaded element 18 is adapted to receive an internallythreaded hollow sleeve 22 provided with an inwardly extending flange 23which defines an opening 23a within which the socket 16 of the tubularmember 12 is axially movable; Within the space 26a of annular form,between the inner tubular member 13 and hollow sleeve 22, is disposed ahelical spring 26 having one end thereof bearing against the element 18and the other end thereof bearing against anannular washer 24. The outertubular member 12 is provided with an outwardly extending flange 25which, in the position illustrated in Fig. 2, is disposed between theannular washer 24 and flange 23.-

The socket 16 of the outer tube 12 is formed with an axially extendingelongated slit 27 through which extends a set screw 28 that threadedlyengages a hollow bushing 30 fixed to the inner tubular member 13 at anopening 30a therein. With this arrangement, the outer and inner tubularmembers 12 and 13 cannot be rotated with respect to one another and areonly axially movable toward and from one another. If desired, thetubular members 12 and 13 may be locked together by the set screw 28, awasher 29 being provided on thelatter to hold the members in any desiredposition with respect to one another.

Assuming that the set screw 28 is turned to permit the inner and outertubular members 12 and 13 to move axially with respectto one another, itwill be understood that the helical spring 26, which'is'undercompression and is disposed between the element 18 and the outwardlyextending shoulder 25 of the outer tubular member 12, acts to move themembers 12 and 13 apart as far as possible until theshoulder 25 engagesthe inwardly extending flange 23 of the hollow sleeve 22. Since thehollow sleeve 22 is in threaded engagement with the element 18, thehollow sleeve 22 and element18 form unitary parts of the inner tubularmember 13. By shifting the hollow sleeve 22 axially on the threadedelement 18, the extreme right-hand end 13a of the inner tubular member13 can be moved nearer or farther from the flange 23 to determine theextent to which the slot 17 is uncovered by the inner tubular member 13when the tubular members 12 and 13 are separated as far as possible, asseen in Fig. 2.

The tubular members 12 and 13 can be moved toward one another againstthe compression of the spring 26 until the extreme end 13a of the innertubular member 13 engages the shoulder 31 of the outer tubular member12. Under these conditions, the members 12 and 13 are as close togetheras possible and the slot 17 in the outer tubular member 12 is completelyclosed by the end of the inner tubular member 13.

When the wand formed by the telescopically fitting tubes 12 and 13 isbeing'moved backward and forward to move the nozzle 14 or other cleaningappliance back and forth over a horizontal surface to be cleaned, thesuction regulator 15 just described functions automatically to vary theextent to which the slot 17 is covered by the inner tube 13 and therebyregulate the suction effect transmitted through the suction line fromthe cleaner casing 10 to the nozzle 14 whose suction inlet 14a remainsthe same in size during the forward and backward movements of thenozzle.

When the suction cleaner is being operated and the inclined wand formedby the telescopically fitting tubes 12 and 13 is being moved forwardover a surface being cleaned, for example, there is a natural tendencyfor an operator to press the upper tubular member 12 of the inclinedwand downwardly and force the nozzle against the surface during itsforward movement over the surface. Under these conditions, downwardmovement is imparted to the socket 16 of the upper tubular member 12with respect to the lower tubular member 13. An upwardly directedreaction force is also developed in the lower tubular member 13 due tofriction produced between the nozzle 14 and the surface being cleaned.As the result of the upward and downward forces produced when the wandis being moved forward on the surface being cleaned, the outer and innertubes 12 and 13 are moved toward one another against the compression ofthe spring 26 and the slot 17 will be closed by the upper end of theinner tube 13. Hence, downward movement is imparted to the upper tubularmember 12 with respect to the lower tubular member 13 to close theopening 17, such movement being responsive to the downwardly directedforce applied by an operator at an acute angle to the vertical, alongthe axis of the inclined wand, during the forward movement of thesuction nozzle 14 over the surface with its suction inlet 14a in goodphysical contact therewith.

When the inclined wand is subsequently moved backward while the uppertubular member 12 is being held by the operator, a predominatelydownward force is no longer applied to the inclined wand along its axisand such downward force may be replaced by a lifting force. Also, thenozzle 14 while being moved backward with its suction inlet 14a inphysical contact withthe surface may exert a dragging efiFect on surfacetending to resist movement thereof. Under these conditions, the forcesproduced longitudinally of the wand act to separate the outer and innertubes 12 and 13 thereof, with separation of the tubes being promoted bythe biasing action of the spring 26 which is under compression. When theouter and inner tubes 12 :and ;13.move apart in this manner,-

the extent to which the slot 17 is covered or closed by the inner tube13 is reduced. Hence, longitudinal movement is imparted to the uppertubular member 12 to increase the size of the opening 17 responsive tothe horizontal component of the force applied by an operator to theinclined wand during the rearward stroke of the suction nozzle 14 overthe surface with its suction inlet 14a in good physical contacttherewith. Irrespective of the size of the opening or slot 17 and evenwhen the opening is fully closed, suction effect will always betransmitted through the wand to the nozzle 14.

In view of the foregoing, it will now be understood that the suctionregulator 15 functions automatically responsive to a condition incidentto the cleaning operation being performed to regulate the manner inwhich suction eflect is transmitted through the suction line from thecleaner casing 10 to the nozzle 14. When the nozzle 14 is being movedforward with its suction inlet 14a in good physical contact with thesurface being cleaned, the slot 17 is closed by the upper end of theinner tube 13 in the manner described above. Under such an operatingcondition, when the floor covering or rug is perfectly smooth andstretched out due to the operator standing on a part thereof, it is ofdistinct advantage to transmit maximum suction through the suction lineto the cleaning nozzle 14 when the latter is being pressed against thesurface being cleaned.

When the nozzle 14 is subsequently being moved backward with its suctioninlet 14a in good physical contact with the surface, the slot 17 is nolonger covered by the inner tube 13 so that a part of the suction effectproduced in the suction line is lost. Due to leakage of suction at theuncovered slot 17, less suction effect is transmitted to the nozzle 14whose suction inlet 14a is still in good physical contact with thesurface being cleaned, thereby reducing the tendency of the rug or otherfloor covering to be drawn to the nozzle. When the suction effecttransmitted to the suction inlet 14a of the nozzle 14 is reducedsufiiciently during backward movement of the inclined wand, a lightscatter rug will remain smoothly on a floor even when the cleaningnozzle is moved toward the center of the rug from a region beyond anouter edge thereof.

Since the hollow sleeve 22 is axially movable on the inner tube 13, theend 13a of the tube may be adjusted with respect to the slot 17 todetermine the maximum size opening produced in the tube 13 when thetubes 12 and 13 are moved apart as far as possible and the slot 17 isuncovered. If desired, the set screw 28 may be employed to lock theouter and inner tubes 12 and 13 so that the slot 17 will remaincompletely closed and render the suction regulator 15 ineffective. Also,the set screw 28 may be employed to lock the tubes 12 and 13 in such amanner that the slot 17 will be in a partially open position and remainin such fixed open position during both forward and backward strokes ofthe wand and nozzle 14 attached thereto.

Although I do not wish to be limited thereto, the element 18 and hollowsleeve 22 desirably may be formed of a suitable plastic like nylon, forexample. A plastic of a type like nylon has a relatively smallcoefiicient of friction and possesses an inherent lubricating qualitywhich makes it possible to shift the hollow sleeve 22 axially of thethreaded element 18 without any difficulty.

Although I have shown and described a single embodiment of my improvedsuction regulator, I do not desire my invention to be limited to theparticular arrangement set forth, and I intend in the succeeding claimsto cover all modifications which do not depart from the spirit and scopeof my invention.

What I claim is:

1. A vacuum cleaner having a suction line including a nozzle having asuction inlet and an elongated hollow wand, means connectingthenozzle'and the wand, said connecting means being'so constructed andarranged that when the nozzle is in its normal operating position on ahorizontal surface to be cleaned with its suction inlet in physicalcontact therewith, the wand is at an acute angle to the vertical, meanscomprising the wand for manually moving the nozzle forward and rearwardon the surface with its suction inlet in physical contact with thesurface during such movement, the elfective size of the suction inlet ofthe nozzle being the same during the forward and rearward movementsthereof, the wall of the wand having an opening, structure embodied inthe wand for decreasing the size of the opening during forward movementsof the nozzle responsive to force applied downwardly on the inclinedwand along its axis when manually moving the nozzle forward with itssuction inlet in physical contact with the surface, and said structureincluding means for increasing the size of the opening in the wandduring rearward movement of the nozzle responsive to a pulling forcehaving a horizontal component applied to the inclined wand when manuallymoving the nozzle rearward with its suction inlet in physical contactwith the surface, said structure being so constructed and arranged that,irrespective of the size of the opening in the wand and even when theopening is fully closed, suction efiect will always be transmittedthrough the wand to the nozzle.

2. Apparatus as set forth in claim 1 in which the elongated wandcomprises a pair of telescopically fitting tubes formed to provide theopening in the wand which varies in size with relative axial movement ofthe tubes, the

means for increasing the size of the opening including resilient meansfor biasing the tubes apart, and means for limiting the extent the tubescan be moved apart.

3. Apparatus as set forth in claim 2 including means for adjusting thecompression of the resilient means.

4. Apparatus as set forth in claim 1 in which the elongated wandcomprises a pair of telescopically fitting tubes, one of the tubeshaving the opening and the other tube being movable past the opening,the means for increasing the size of the opening including resilientmeans for biasing the tubes apart, and means for limiting the extent thetubes can be moved apart.

5. Apparatus as set forth in claim 4 including means for locking thetubes together in any one of several positions between closed and fullyopen positions of the opening.

References Cited in the file of this patent UNITED STATES PATENTSGermany Oct. 31, 1928

